Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 Mar 10;3(1):ENEURO.0138-15.2016. doi: 10.1523/ENEURO.0138-15.2016

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2016 Case et al.

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.

PMC Copyright notice

Figure 1. — Pleasantness and intensity of brushing in healthy participants and chronic pain patients. Healthy participants and FM patients rated the pleasantness (A, B) and intensity (C, D) of slow (CT-optimal) and fast brushing of the left forearm on the corresponding VAS scales. Mean ratings at baseline (before any drug administration) are displayed; error bars show SD. *Two-tailed Tukey test, p < 0.05. Lines display individual participant data. There was a significant main effect of brushing speed (slow vs fast) on pleasantness ratings (F_(1,50) = 3.56, one-tailed p = 0.032 ^a; without males: F_(1,46) = 3.76, one-tailed p = 0.027) but no main effect of group (healthy vs FM; F_(1,50) = 0.41, one-tailed, p = 0.26 ^b; without males: F_(1,46) = 0.32, one-tailed, p = 0.26). There was a significant interaction between brushing speed and group (F_(1,50) = 3.32, one-tailed, p = 0.037^c; Cohen’s d = 0.51; without males: F_(1,46) = 3.14, one-tailed, p = 0.04; A shows mean slow–fast ratings). Post hoc Tukey tests showed that healthy participants rated slow brushing as significantly more pleasant than fast brushing (Tukey, p = 0.042), whereas FM participants did not (Tukey, p = 1.00; A shows mean slow–fast ratings). Age did not affect ratings of brushing pleasantness or interact with speed in healthy participants (F_(1,26) = 0.03, p = 0.86^d; F_(1,26) = 0.09, p = 0.76^e) or in FM patients (F_(1,22) = 0.56, p = 0.46^f; F_(1,22) = 3.08, p = 0.09^g). When depression and anxiety were added to the model, depression significantly predicted pleasantness ratings (F_(1,46) =4.28, p = 0.04); anxiety did not (F_(1,46) = 0.42, p = 0.52). Including these ratings in the model strengthened the group by speed interaction (F_{(1, 48)} = 4.42, two-tailed, p = 0.041). There was a significant main effect of speed of brushing (slow vs fast) on intensity ratings (F_(1,50) = 4.26, p < 0.001^h; without males: F_(1,46) = 20.0, p < 0.001) but no main effect of group (healthy vs FM; F_(1,50) = 0.32, one-tailed, p = 0.58 ⁱ; without males: F_(1,46) = 0.19, two-tailed p = 0.67). There was a significant interaction between brushing speed and participant group (F_(1,50) = 4.26, p = 0.044 ^j; Cohen’s d = 0.57; without males: F_(1,46) = 4.42, p = 0.041^,). Post hoc Tukey tests showed that healthy participants rated fast brushing as more intense than slow brushing (Tukey p < 0.001), whereas FM participants did not (Tukey p = 0.24; B shows mean slow–fast ratings). Age did not affect ratings of brushing intensity or interact with speed in either healthy participants (F_(1,26) = 1.09, p = 0.31^k; F_(1,26) = 0.11, p = 0.75^l) or FM patients (F_(1,22) = 0.01, p = 0.93^m; F_(1,22) = 0.05, p = 0.83ⁿ). Anxiety significantly predicted pleasantness ratings (F_(1,46) = 6.66, p = 0.01); depression did not (F_(1,46) = 1.34, p = 0.25). Including these ratings in the model weakened the group by speed interaction (F_(1,48) = 3.67, two-tailed p = 0.061).